The UPML Framework, IRS-I and IRS-II John Domingue, Liliana Cabral & Enrico Motta Knowledge Media Institute The Open University, UK

Outline Overview of web services UPML – knowledge level modelling paradigm Classification Library IRS-I Demo –quickly configuring an apple classifier IRS-II – capability driven web service invocation Patient Shipping Scenario (Demo) Preparation for afternoon hands on session

Web Service in a nutshell Web of documents -> web of reusable software components A piece of software available over the Internet which can be invoked through a standardized (normally XML-based) messaging system

Service Registry Service Requester Service Provider Service Description Web Service Publish Find Bind WS – Usage scenario

What’s the big deal? In U.S. Web Services Market Analysis, 2002 IDC predicts that Web services will become the dominant distributed computing architecture in the next 10 years. Web services will drive software, services and hardware sales of $21 billion in the U.S. by 2007 and will reach $27 billion in Web services promise easy access to remote content and application functionality, independently of the provider's platform, the location, the service implementation, or the data format. Kuassi Mensah, Oracle Exposure of capabilities

Application Areas E-commerce –Integrating supply chains, Brokering, Shopping bots, etc.. E-science –Data Analysis, Discovery, Integration, etc.. Knowledge Management –Information search, personalization,

Limitations of WS Technology Manual Discovery Manual Invocation Manual (ad hoc) Mediation Manual (ad hoc) Composition

Semantic differences remain the primary roadblock to smooth application integration, one which Web Services alone won't overcome. Until someone finds a way for applications to understand each other, the effect of Web services technology will be fairly limited. When I pass customer data across [the Web] in a certain format using a Web Services interface, the receiving program has to know what that format is. You have to agree on what the business objects look like. And no one has come up with a feasible way to work that out yet -- not Oracle, and not its competitors Oracle Chairman and CEO Larry Ellison

Positioning Semantic Web Services Web (URI, HTML, HTTP) Web Services (UDDI, WSDL, SOAP) Semantic Web (RDF, OWL) Semantic Web Services Dynamic Static Syntax Semantics

Motivation Mismatch between users view and web service functionalities –Requires web service centred and user (community) centred semantic representations Users want to carry out tasks or achieve goals Richer semantics required for automatic web service location, selection, mediation, composition, brokering

UPML Framework

Classification Classification can be seen as the problem of finding the solution (class), which best explains a set of known facts (observables), according to some criterion Solution Observables Candidate Sols. Classification Solution Criterion

Example Observables Candidate Sols. Criterion Classification Solution {background=green; area=china...} Complete-coverage-criterion (every observable has to be explained) {chinese-granny, dutch-granny, etc..} {chinese-granny}

Classification Task Ontology 70 Definitions Provides both a theory of classification and a vocabulary to describe classification problems Ontology is separated from task specifications

Generic Classification Task Input roles –Candidate Solutions, Match Criterion, Solution Criterion, Observables Output Roles –Solutions Precondition –Both observables and candidate solutions have to be provided Goal –To find a solution from the candidate solutions which is admissible with respect to the given observables, solution criterion and match criterion

Classification Task (1/2)

Classification Task (2/2)

Specific Classification Tasks Single-Solution Classification Task –Single-solution assumption Optimal Classification Tasks –Goal requires optimality

Problem Solving Library Based on heuristic classification model Includes both data-directed and solution-directed methods Supported by a method ontology

Heuristic Classification Model Clancey, AI Journal, 27, 1985 Heuristic Match Abstraction Data Abstractions Solutions Abstractions Refinement Solutions

Method Ontology: Main Concepts Abstractors –Mechanism for performing abstraction on observables –Abstractor: Obs* -> Obs Refiners –Mechanism for specialising a solution –Refiner: Sol -> Sol* Candidate Exclusion Criterion –A criterion which is used to decide when a search path is a dead-end –Default criterion rules out inconsistent solutions

3 Heuristic Classification PSMs Two Data-directed –Admissible Solution Classifier Finds one admissible solution according to the given criteria Uses backtracking hill climbing –Optimal Classifier Performs complete search looking for optimal solution Uses best-first strategy Uses candidate exclusion criterion to prune search space One Solution-directed –Goes down the solution hierarchy, acquiring observables as needed –Ask for observables with max discrimination power

Task-Method Hierarchy

Example Apple Domain –Originally developed in Amsterdam Solutions = Apple Types = {granny, noble, delicious...} Hierarchy of Apple Types Features = {bkg-colour, fg-colour, rusty....} Pretty trivial really!

Demo

IRS-II: Integrating UPML and Web Services

The Internet Reasoning Service is an infrastructure for publishing, locating, executing and composing semantic web services, organized according to the task/method/domain framework

Features of IRS-II (1/2) Based on Soap messaging standard Provides API for client applications Provides built-in brokering and service discovery support Provides capability-centred service invocation

Features of IRS-II (2/2) Publishing support for variety of platforms –Java, Lisp, Web Applications, Java Web Services Enables publication of ‘standard code’ –Provides clever wrappers automatically, which turn code into web services –One-click publishing of web services Integrated with standard Web Services world –Published code appears as Semantic web service to IRS ‘Ordinary’ web service to web service world

Task Spec (def-class exchange_rate_provision (goal-specification-task) ?task ((has-input-role :value has_source_currency :value has_target_currency) (has-output-role :value has_exchange_rate) (has_source_currency :type currency :cardinality 1) (has_target_currency :type currency :cardinality 1) (has_exchange_rate :type positive-number) (has-precondition :value (kappa (?psm) (and (currency (role-value ?psm has_source_currency)) (currency (role-value ?psm has_target_currency))))) (has-goal-expression :value (kappa (?psm ?sol) (= ?sol (the_official_exchange_rate (role-value ?psm has_source_currency) (role-value ?psm has_target_currency)))))))

Grounding Soap-based Done at task level

Toplevel Exchange Rate Method (def-class exchange-rate-provider (primitive-method) ?psm ((has-input-role :value has_source_currency :value has_target_currency) (has-output-role :value has-exchange-rate) (has_source_currency :type currency :cardinality 1) (has_target_currency :type currency :cardinality 1) (has-exchange-rate :type positive-number) (has-precondition :value (kappa (?s) (stock_available (role-value ?psm has_target_currency))))))

Exchange Rate Methods (def-class european-exchange-rate-provider (exchange-rate-provider) ?psm () :own-slots ((applicability-condition (kappa (?psm) (european-currency (role-value ?psm 'has_source_currency)))) (tackles-task-type exchange_rate_provision))) (def-class non-european-exchange-rate-provider (exchange-rate-provider) ?psm () :own-slots ((applicability-condition (kappa (?psm) (non-european-currency (role-value ?psm 'has_source_currency)))) (tackles-task-type exchange_rate_provision)))

IRS Server Domain Models Method Specifications + Registry of Implementors Task Specifications + SOAP Binding IRS Publisher S O A P IRS Client SOAP IRS Publisher Lisp Java Java WS IRS-II Framework

Patient Shipping Scenario

Money Related Services

Medical Related Services

Patient Shipping Demo

Task Spec

Method Spec

Supporting Definitions

Hospital Bed Service Task

Hospital Bed Service PSM

Hip Hip Hospital PSM

Multiple Hospital PSMs

Valid Relations Classes are unary relations –e.g. (currency ?x) Slots are binary relations –e.g. (has-author ?x ?y) Standard relations in akt-reference ontology =, ==,, member

Java API achieveTask createOntology getOntologyProperties updateOntologyProperties deleteOntology saveTaskDescription getTaskDescription deleteTaskDescription savePSMDescription getPSMDescription deletePSMDescription publishHttpGetRequest publishLispFunction publishJavaClass publishWebServiceWSDL

LispWeb Server IRS-II Architecture IRS-II Server PSM Publisher Registry OCML UPML Library Wilbur OWL-S Handler OWL Handler OWL OWL-S RDF Browser Invocation Client Task/PSM Editors Publishing Clients SOAP Handler SOAPSOAP Publishing Platforms Web Service Java Code Web Application SOAP Browser Handler Publisher Handler Invocation Handler JavaAPIJavaAPI

Generic Publishing Platform Architecture IRS-II Publishing Platform HTTP Server SOAP Handler Service Registrar Service Invoker PSM Service Registry IRS-II Server Invocation Client SOAP Publishing Clients SOAP Web Service 1 Web Service 2 Web Service 3 Web Service 4

IRS Browser/Editor Demo User Name: knowledgeweb Password: summerschool

IRS, OWL-S and WSMO IRS-II and WSMO model user requests (task or goal) –IRS-II has task (goal) based invocation IRS-II and WSMO model mediation OWL-S and WSMO include non-functional properties WSMO splits composition into orchestration and choreography Formalisms –OWL-S: OWL – DL (handling conditions?) –IRS-II: OCML (import/export to RDF(S), OWL, OWL-S, WSMO (planned)) –WSMO: WSML- F-Logic (OWL Compatibility?)

Summary Web services require rich semantic annotation to automate location selection, mediation etc UPML framework composed of ontology supported tasks, problem solving methods and domain models Classification Library IRS-II integrates web services with PSMs PSMs tied to tasks via tackles task and applicability conditions

A Stack of Standards? HTTP XML-S XML SOAP WSDL UDDI BEPL4 WS URI WS- CDL RDF RDF-S OWL WSML OWL-S WSMO WSMX IRS-III